As you notice here, the Cloudant DB connector resource name follows "couchdb/[service_name]" naming which is ("couchdb/todos-cloudant" in our case). Note that all of the Cloudant DB connector resources have the prefix "couchdb/". _db connector variable is used to access the Cloudant Database which is created in Bluemix as shown below.

As you see we have a Liberty for Java app called ("todos") and a Cloudant Database service which is bound to it. Do not forget to make sure your Cloudant service name matches the last part of the Cloudant DB connector name after “/”.

The mentioned example above introduces JAX-RS with Cloudant to show you how you can use them together with Bluemix and to give you the ability to decouple the REST client JavaScript code from the underlying Cloudant Database structure which will give you the ability to change Cloudant DB JSON structure in the future without affecting your REST API clients code.